2025
Cognitive functioning and functional ability in women with schizophrenia and homelessness
Menon J, Kantipudi S, Mani A, Radhakrishnan R. Cognitive functioning and functional ability in women with schizophrenia and homelessness. Schizophrenia Research Cognition 2025, 39: 100338. DOI: 10.1016/j.scog.2024.100338.Peer-Reviewed Original ResearchWorld Health Organization Disability Assessment ScaleFrontal Assessment BatteryCognitive functionCognitive dysfunctionScale for Assessment of Negative SymptomsAssessment of Negative SymptomsDisability Assessment ScaleStudies of schizophreniaHigher cognitive dysfunctionPremorbid level of functionCognitive function of womenNegative symptomsAssessment batteryPremorbid levelSchizophreniaCognitive AssessmentCognitive impairmentSemi-structured proformaDementia ScaleLevel of functionAssessment ScalePsychosocial factorsHigher literacy levelsGroup of womenFunctional ability
2024
11C-UCB-J PET imaging is consistent with lower synaptic density in autistic adults
Matuskey D, Yang Y, Naganawa M, Koohsari S, Toyonaga T, Gravel P, Pittman B, Torres K, Pisani L, Finn C, Cramer-Benjamin S, Herman N, Rosenthal L, Franke C, Walicki B, Esterlis I, Skosnik P, Radhakrishnan R, Wolf J, Nabulsi N, Ropchan J, Huang Y, Carson R, Naples A, McPartland J. 11C-UCB-J PET imaging is consistent with lower synaptic density in autistic adults. Molecular Psychiatry 2024, 1-7. PMID: 39367053, DOI: 10.1038/s41380-024-02776-2.Peer-Reviewed Original ResearchPositron emission tomographySynaptic densityAutistic adultsBrain regionsAutistic featuresClinical phenotype of autismNon-autistic participantsPhenotype of autismNon-autistic individualsRelationship to clinical characteristicsSynaptic vesicle glycoprotein 2AAssociated with clinical measuresPost-mortem studiesPositron emission tomography scanPrefrontal cortexClinician ratingsAutism groupNeural basisBrain areasNeural processesBetween-group differencesVolumetric differencesBinding potentialDensity of synapsesAutismEfficacy and Safety of Ketamine/Esketamine in Bipolar Depression in a Clinical Setting.
Santucci M, Ansari M, Nikayin S, Radhakrishnan R, Rhee T, Wilkinson S. Efficacy and Safety of Ketamine/Esketamine in Bipolar Depression in a Clinical Setting. The Journal Of Clinical Psychiatry 2024, 85 PMID: 39361411, DOI: 10.4088/jcp.24m15376.Peer-Reviewed Original ResearchConceptsBipolar depressionAcute seriesRisk of affective switchDiagnosis of bipolar depressionRefractory bipolar depressionAcute phaseMADRS scoreAffective switchIntranasal esketamineManic episodesBipolar disorderCohort of patientsAttending psychiatristsSource of morbidityEsketamineSample of patientsIV ketamineMaintenance treatmentDepressionClinical responseHeightened riskClinical outcomesMania/hypomaniaKetamineKetamine/esketamineSubstance use and spine density: a systematic review and meta-analysis of preclinical studies
Oliva H, Prudente T, Nunes E, Cosgrove K, Radhakrishnan R, Potenza M, Angarita G. Substance use and spine density: a systematic review and meta-analysis of preclinical studies. Molecular Psychiatry 2024, 29: 2873-2885. PMID: 38561468, DOI: 10.1038/s41380-024-02519-3.Peer-Reviewed Original ResearchSpine densityPrefrontal cortexSubstance useDrug self-administrationHippocampal spine densityEffects of cocaineSubstance use disordersConvergence of findingsSpine density changesSubstances of abuseMeta-analysis of preclinical studiesNucleus accumbensBehavioral sensitizationSelf-administrationBrain mechanismsPreclinical studiesBrain regionsMorphine effectsSynaptic density changesMeta-analysisAmphetamineSynaptic densityCocaineModerate-to-highCortexIn Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect?
Radhakrishnan R. In Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect? Biological Psychiatry 2024, 95: 605-607. PMID: 38479976, DOI: 10.1016/j.biopsych.2024.01.016.Peer-Reviewed Original ResearchConceptsSynaptic densityA systematic review of approaches to improve medication adherence in homeless adults with psychiatric disorders
Hird R, Radhakrishnan R, Tsai J. A systematic review of approaches to improve medication adherence in homeless adults with psychiatric disorders. Frontiers In Psychiatry 2024, 14: 1339801. PMID: 38260790, PMCID: PMC10800888, DOI: 10.3389/fpsyt.2023.1339801.Peer-Reviewed Original ResearchMedication adherenceAssertive community treatmentLong-Acting Injectable MedicationsPsychiatric disordersInjectable medicationsAdherence enhancementCommunity treatmentHomeless adultsSystematic reviewPsychiatric medication adherenceSubstance use disordersFull-text reviewModified therapeutic communityPeer-reviewed journalsInpatient interventionLarge RCTsSelf-designed scaleHomeless individualsOutpatient interventionInpatient carePharmacy clinicObservational studyInclusion criteriaUse disordersPeer-reviewed studies
2023
PET Biomarkers in Psychiatry
Orhii P, Radhakrishnan R, Selvaraj S. PET Biomarkers in Psychiatry. 2023, 81-104. DOI: 10.1007/978-3-031-43356-6_6.Peer-Reviewed Original ResearchThe regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J
Toyonaga T, Khattar N, Wu Y, Lu Y, Naganawa M, Gallezot J, Matuskey D, Mecca A, Pittman B, Dias M, Nabulsi N, Finnema S, Chen M, Arnsten A, Radhakrishnan R, Skosnik P, D’Souza D, Esterlis I, Huang Y, van Dyck C, Carson R. The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J. European Journal Of Nuclear Medicine And Molecular Imaging 2023, 51: 1012-1022. PMID: 37955791, DOI: 10.1007/s00259-023-06487-8.Peer-Reviewed Original ResearchSynaptic densityAge-related decreaseMagnetic resonance imagingBlood flowAge-related synaptic lossGray matter volume lossSynaptic density lossPositron emission tomography (PET) ligandSynaptic vesicle glycoprotein 2AVivo PET measurementsMedial occipital cortexGray matter volumeAge-related neurodegenerationGray matter regionsCognitive normal subjectsAge-related changesSynaptic lossNerve terminalsWide age rangeOccipital cortexTomography ligandNormal subjectsGM volumeAge-related functional lossesMatter volumeSubstance Use Disorder and Health Outcomes in COVID-19—The Need for a Better Research Method to Determine Substance Use Exposure
Christian N, Zhou X, Radhakrishnan R. Substance Use Disorder and Health Outcomes in COVID-19—The Need for a Better Research Method to Determine Substance Use Exposure. JAMA Psychiatry 2023, 80: 968-968. PMID: 37405794, DOI: 10.1001/jamapsychiatry.2023.2113.Peer-Reviewed Original ResearchA leaky umbrella has little value: evidence clearly indicates the serotonin system is implicated in depression
Jauhar S, Arnone D, Baldwin D, Bloomfield M, Browning M, Cleare A, Corlett P, Deakin J, Erritzoe D, Fu C, Fusar-Poli P, Goodwin G, Hayes J, Howard R, Howes O, Juruena M, Lam R, Lawrie S, McAllister-Williams H, Marwaha S, Matuskey D, McCutcheon R, Nutt D, Pariante C, Pillinger T, Radhakrishnan R, Rucker J, Selvaraj S, Stokes P, Upthegrove R, Yalin N, Yatham L, Young A, Zahn R, Cowen P. A leaky umbrella has little value: evidence clearly indicates the serotonin system is implicated in depression. Molecular Psychiatry 2023, 28: 3149-3152. PMID: 37322065, PMCID: PMC10618084, DOI: 10.1038/s41380-023-02095-y.Peer-Reviewed Original ResearchImpact of personal beliefs about medical cannabis on physician recommendation practices: Results of an international survey
Syed S, Singh J, Elkholy H, Rojnić Palavra I, Tomicevic M, Eric A, Pinto da Costa M, Guloksuz S, Radhakrishnan R. Impact of personal beliefs about medical cannabis on physician recommendation practices: Results of an international survey. Asian Journal Of Psychiatry 2023, 85: 103634. PMID: 37257363, DOI: 10.1016/j.ajp.2023.103634.Peer-Reviewed Original ResearchRole of Psychedelics in Treatment-Resistant Depression
Kamal S, Jha M, Radhakrishnan R. Role of Psychedelics in Treatment-Resistant Depression. Psychiatric Clinics Of North America 2023, 46: 291-305. PMID: 37149346, DOI: 10.1016/j.psc.2023.02.004.Peer-Reviewed Original Research
2022
Age, gender and body-mass-index relationships with in vivo CB1 receptor availability in healthy humans measured with [11C]OMAR PET
Radhakrishnan R, Worhunsky PD, Zheng MQ, Najafzadeh S, Gallezot JD, Planeta B, Henry S, Nabulsi N, Ranganathan M, Skosnik PD, Pittman B, Cyril D'Souza D, Carson RE, Huang Y, Potenza MN, Matuskey D. Age, gender and body-mass-index relationships with in vivo CB1 receptor availability in healthy humans measured with [11C]OMAR PET. NeuroImage 2022, 264: 119674. PMID: 36243269, DOI: 10.1016/j.neuroimage.2022.119674.Peer-Reviewed Original ResearchBidirectional relationships between cannabis use, anxiety and depressive symptoms in the mediation of the association with psychotic experience: further support for an affective pathway to psychosis
Radhakrishnan R, Pries LK, Erzin G, Have M, de Graaf R, van Dorsselaer S, Gunther N, Bak M, Rutten BPF, van Os J, Guloksuz S. Bidirectional relationships between cannabis use, anxiety and depressive symptoms in the mediation of the association with psychotic experience: further support for an affective pathway to psychosis. Psychological Medicine 2022, 53: 5551-5557. PMID: 36093677, PMCID: PMC10482707, DOI: 10.1017/s0033291722002756.Peer-Reviewed Original ResearchConceptsAnxiety/depressive symptomsDepressive symptomsCannabis usePE incidencePsychotic experiencesFirst longitudinal cohort studyNetherlands Mental Health SurveyLongitudinal cohort studyMental Health SurveyRole of cannabisBidirectional relationshipCohort studyHealth SurveyIncidence studyAffective symptomsSymptomsCannabisEducation statusLongitudinal studyPsychosisIncidenceAnxietyTemporal relationshipMediation analysisFurther supportThe association between cannabis use and facial emotion recognition in schizophrenia, siblings, and healthy controls: Results from the EUGEI study
Fusar-Poli L, Pries LK, van Os J, Radhakrishnan R, Pençe AY, Erzin G, Delespaul P, Kenis G, Luykx JJ, Lin BD, Akdede B, Binbay T, Altınyazar V, Yalınçetin B, Gümüş-Akay G, Cihan B, Soygür H, Ulaş H, Cankurtaran EŞ, Kaymak SU, Mihaljevic MM, Andric-Petrovic S, Mirjanic T, Bernardo M, Mezquida G, Amoretti S, Bobes J, Saiz PA, García-Portilla MP, Sanjuan J, Aguilar EJ, Santos JL, Jiménez-López E, Arrojo M, Carracedo A, López G, González-Peñas J, Parellada M, Maric NP, Atbaşoğlu C, Üçok A, Alptekin K, Saka MC, investigators G, Aguglia E, Arango C, Rutten BP, Guloksuz S. The association between cannabis use and facial emotion recognition in schizophrenia, siblings, and healthy controls: Results from the EUGEI study. European Neuropsychopharmacology 2022, 63: 47-59. PMID: 36055075, DOI: 10.1016/j.euroneuro.2022.08.003.Peer-Reviewed Original ResearchConceptsHealthy controlsCannabis useDegraded Facial Affect Recognition TaskPresent cross-sectional studyCross-sectional studyHigh genetic riskProgression of schizophreniaRegular cannabis useCognitive disturbancesRegular cannabisPsychosis riskPatientsSchizophreniaFacial emotion recognition performanceGenetic riskCannabisCurrent cannabisEUGEI studyLongitudinal studyAgeSiblingsAssociationRiskOnsetEffect relationshipImpact of Cannabis Use, Substance Use Disorders, and Psychiatric Diagnoses on COVID-19 Outcomes: A Retrospective Cohort Study.
Ramakrishnan D, Sureshanand S, Pittman B, Radhakrishnan R. Impact of Cannabis Use, Substance Use Disorders, and Psychiatric Diagnoses on COVID-19 Outcomes: A Retrospective Cohort Study. The Journal Of Clinical Psychiatry 2022, 83 PMID: 36044600, DOI: 10.4088/jcp.21m14332.Peer-Reviewed Original ResearchConceptsCOVID-19 outcomesSubstance use disordersOpioid use disorderCOVID-19 patientsAlcohol use disorderRetrospective cohort studyVentilatory supportICU admissionUse disordersHospital admissionPsychiatric diagnosisCohort studyIntensive care unit admissionCOVID-19 positive patientsCare unit admissionLength of hospitalizationLarge health care systemMultivariable logistic regressionHigh-risk groupNumber of hospitalizationsBenzodiazepine use disorderCannabis use disorderUrine toxicology reportsElectronic medical recordsCocaine use disorderIllness Phase as a Key Assessment and Intervention Window for Psychosis
Kohler C, Wolf D, Abi-Dargham A, Anticevic A, Cho Y, Fonteneau C, Gil R, Girgis R, Gray D, Grinband J, Javitch J, Kantrowitz J, Krystal J, Lieberman J, Murray J, Ranganathan M, Santamauro N, Van Snellenberg J, Tamayo Z, Group T, D'Souza D, Srihari V, Gueorguieva R, Patel P, Forselius-Bielen K, Lu J, Butler A, Fram G, Afriyie-Agyemang Y, Selloni A, Cadavid L, Gomez-Luna S, Gupta A, Radhakrishnan R, Rashid A, Aker R, Abrahim P, Nia A, Surti T, Kegeles L, Carlson M, Goldberg T, Gangwisch J, Benedict E, Govil P, Brazis S, Mayer M, de la Garrigue N, Fallon N, Baumvoll T, Abeykoon S, Perlman G, Bobchin K, Elliott M, Schmidt L, Rush S, Port A, Heffernan Z, Laney N, Kantor J, Hohing T, Gur R, Gur R, Calkins M. Illness Phase as a Key Assessment and Intervention Window for Psychosis. Biological Psychiatry Global Open Science 2022, 3: 340-350. PMID: 37519466, PMCID: PMC10382701, DOI: 10.1016/j.bpsgos.2022.05.009.Peer-Reviewed Original ResearchIllness phasePotential critical windowsPhase-specific biomarkersDopaminergic abnormalitiesFunctional outcomeSpecialty careSymptom assessmentIllness stageChronic illnessClinical assessmentIllness trajectoryNeurophysiological biomarkersFunctional abnormalitiesClinical careEarly psychosisMemory dysfunctionPsychotic disordersTreatment targetsAllostatic adaptationIntervention windowClinical programsBrain developmentCritical windowDysfunctionIllnessEditorial: Gone to Pot: Examining the Association Between Cannabis Use and Medical/Psychiatric Disorders
Radhakrishnan R, Guloksuz S, D'Souza DC, van Os J. Editorial: Gone to Pot: Examining the Association Between Cannabis Use and Medical/Psychiatric Disorders. Frontiers In Psychiatry 2022, 13: 837757. PMID: 35211046, PMCID: PMC8861305, DOI: 10.3389/fpsyt.2022.837757.Peer-Reviewed Original Research
2021
Dopamine D1R Receptor Stimulation as a Mechanistic Pro-cognitive Target for Schizophrenia
Abi-Dargham A, Javitch JA, Slifstein M, Anticevic A, Calkins ME, Cho YT, Fonteneau C, Gil R, Girgis R, Gur RE, Gur RC, Grinband J, Kantrowitz J, Kohler C, Krystal J, Murray J, Ranganathan M, Santamauro N, Van Snellenberg J, Tamayo Z, Wolf D, D’Souza D, Srihari V, Gueorguieva R, Patel P, Forselius-Bielen K, Lu J, Butler A, Fram G, Afriyie-Agyemang Y, Selloni A, Cadavid L, Gomez-Luna S, Gupta A, Radhakrishnan R, Rashid A, Aker R, Abrahim P, Nia A, Surti T, Kegeles L, Carlson M, Goldberg T, Gangwisch J, Benedict E, Govil P, Brazis S, Mayer M, de la Garrigue N, Fallon N, Baumvoll T, Abeykoon S, Perlman G, Bobchin K, Elliott M, Schmidt L, Rush S, Port A, Heffernan Z, Laney N, Kantor J, Hohing T, Gray D, Lieberman J. Dopamine D1R Receptor Stimulation as a Mechanistic Pro-cognitive Target for Schizophrenia. Schizophrenia Bulletin 2021, 48: 199-210. PMID: 34423843, PMCID: PMC8781338, DOI: 10.1093/schbul/sbab095.Peer-Reviewed Original ResearchConceptsCortical dopamine neurotransmissionPositive allosteric modulationImportant therapeutic targetPF-06412562Dopaminergic receptorsD1R stimulationDA levelsTolerable dosesLevel of stimulationDopamine neurotransmissionReceptor stimulationTherapeutic targetPartial agonistCognitive deficitsBiased agonismFull agonismTarget engagementAllosteric modulationNew drugsStimulationPoor bioavailabilitySchizophreniaOptimal stimulationDrugsExpression levelsIn vivo evidence of lower synaptic vesicle density in schizophrenia
Radhakrishnan R, Skosnik PD, Ranganathan M, Naganawa M, Toyonaga T, Finnema S, Hillmer AT, Esterlis I, Huang Y, Nabulsi N, Carson RE, D’Souza D. In vivo evidence of lower synaptic vesicle density in schizophrenia. Molecular Psychiatry 2021, 26: 7690-7698. PMID: 34135473, DOI: 10.1038/s41380-021-01184-0.Peer-Reviewed Original ResearchConceptsSynaptic vesicle densityHealthy controlsVesicle densityHigh-resolution research tomographySynaptic densitySCZ patientsVivo measuresNovel positron emission tomography (PET) ligandGender-matched healthy controlsCumulative antipsychotic exposurePositron emission tomography (PET) ligandSynaptic spine densityPsychosis symptom severityGray matter volumeJ bindingAntipsychotic exposureSpine densityDisease progressionFrontal cortexOccipital cortexTomography ligandTemporal cortexAnterior cingulateVivo findingsParietal cortex